From 1de25a6e87e0e627aa34298105a3d17c60a1f44e Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 26 Oct 2015 19:33:05 +0100 Subject: unzip: test for bad archive SEGVing function old new delta huft_build 1296 1300 +4 Signed-off-by: Denys Vlasenko --- archival/libarchive/decompress_gunzip.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'archival') diff --git a/archival/libarchive/decompress_gunzip.c b/archival/libarchive/decompress_gunzip.c index 7b6f459..30bf451 100644 --- a/archival/libarchive/decompress_gunzip.c +++ b/archival/libarchive/decompress_gunzip.c @@ -305,11 +305,12 @@ static int huft_build(const unsigned *b, const unsigned n, unsigned i; /* counter, current code */ unsigned j; /* counter */ int k; /* number of bits in current code */ - unsigned *p; /* pointer into c[], b[], or v[] */ + const unsigned *p; /* pointer into c[], b[], or v[] */ huft_t *q; /* points to current table */ huft_t r; /* table entry for structure assignment */ huft_t *u[BMAX]; /* table stack */ unsigned v[N_MAX]; /* values in order of bit length */ + unsigned v_end; int ws[BMAX + 1]; /* bits decoded stack */ int w; /* bits decoded */ unsigned x[BMAX + 1]; /* bit offsets, then code stack */ @@ -324,7 +325,7 @@ static int huft_build(const unsigned *b, const unsigned n, /* Generate counts for each bit length */ memset(c, 0, sizeof(c)); - p = (unsigned *) b; /* cast allows us to reuse p for pointing to b */ + p = b; i = n; do { c[*p]++; /* assume all entries <= BMAX */ @@ -365,12 +366,14 @@ static int huft_build(const unsigned *b, const unsigned n, } /* Make a table of values in order of bit lengths */ - p = (unsigned *) b; + p = b; i = 0; + v_end = 0; do { j = *p++; if (j != 0) { v[x[j]++] = i; + v_end = x[j]; } } while (++i < n); @@ -432,7 +435,7 @@ static int huft_build(const unsigned *b, const unsigned n, /* set up table entry in r */ r.b = (unsigned char) (k - w); - if (p >= v + n) { + if (p >= v + v_end) { // Was "if (p >= v + n)" but v[] can be shorter! r.e = 99; /* out of values--invalid code */ } else if (*p < s) { r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is EOB code */ -- cgit v1.1